There are many applications which require high levels of precision and determinism from a network such as real time control systems, cellular networks, and telecommunications systems.
Typically, existing network standards such as SDH/SONET and Synchronous Ethernet (SyncE) are used for these applications. Using carefully designed hardware existing synchronous networks aim to keep the end to end jitter and delay to a minimum.
Synchronous networks may operate with a single clock, this clock typically being embedded within the physical layer protocol. However, implementation of such a system may be relatively expensive. Synchronous networking equipment may be very expensive.
Commercial data centres may use packet based statistically multiplexed networks (STDM) such as Ethernet. STDM may offer scalability due to its volume price benefit and a relatively simple deployment model. However, the time precision and determinism of STDM may not meet some requirements.